The present invention concerns apparatus for controlling energy-consuming loads, and more particularly, a novel control module for controlling at least one load of variable power consumption, responsive to data input from local and/or remote locations.
Conservation of energy is particularly desirable in this day and age. The ability to control the output level of an energy-consuming load, whether from the load location or from a remote location, facilitates many economic advantages. Specifically, the ability to set, from a central facility, the output of each of a plurality of light sources, located in various locations in one or more buildings, is highly desirable. With the advent of variable-output gas-discharge lamps, such mercury-vapor discharge fluorescent lamps and associated electronic ballast, it is desirable to provide a system for controlling, from a local, one or more remote and/or a central location, the output of each individual one of a multiplicity of such energy-conserving lamps.
One method for providing a variable, or "dimmable", output level from a fluorescent lamp is described and claimed in co-pending application Ser. No. 177,835 and one embodiment of an inverter-ballast utilizing the method therein described for control of fluorescent lamp output light level, is described and claimed in co-pending U.S. patent application Ser. No. 177,942 both filed on Aug. 14, 1980 assigned to the assignee of the present invention, and incorporated herein by reference in their entirety. Further, in co-pending U.S. patent application Ser. No. 242,782, filed Mar. 11, 1981, now U.S. Pat. No. 4,345,200 assigned to the assignee of the present invention, and incorporated herein in its entirety by reference, there is described and claimed an input circuit for providing, to the ballast/lamp combination of the aforementioned applications, both an on/off control signal and an output level control signal, responsive to the magnitude of a single D.C. voltage; the D.C. voltage may be provided by conversion, after appropriate electrical isolation, of the amplitude of a periodic A.C. waveform.
Centralized control systems, for remotely controlling each of a multiplicity of loads at various ones of a plurality of locations, are described and claimed in U.S. Pat. No. 4,213,182, issued July 15, 1980; in co-pending U.S. patent applications Ser. No. 323,745, filed Nov. 20, 1981; U.S. patent application Ser. No. 324,372, filed Nov. 23, 1981; U.S. patent application Ser. No. 324,640, filed Nov. 24, 1981; U.S. patent application Ser. No. 326,116, filed Nov. 30, 1981; U.S. patent application Ser. No. 325,031, filed Nov. 25, 1981; U.S. patent application Ser. No. 479,048, filed Mar. 25, 1983; in U.S. patent No. 4,367,414, issued Jan. 4, 1983; and in co-pending U.S. Pat. application Ser. No. 267,328 filed on even date herewith, all assigned to the assignee of the present invention and incorporated herein in their entirety by reference. Further, various cost-effective apparatus for local control of the light output level of such a ballast/lamp combination, requiring manual "dimming" adjustments at the local location and incapable of centralized control, are described and claimed in copending U.S. patent applications Ser. Nos. 235,191, filed Feb. 17, 1981, and 242,780, filed Mar. 11, 1981 assigned to the assignee of the present invention and incorporated herein in their entirety by reference.
It is desirable, as previously mentioned, to be able to control each of several energy-consuming loads to a selected one of a plurality of discrete levels either in a centralized control system or in a "stand-alone" system (wherein each lamp is locally controlled either individually or in a small group of simultaneously controlled lamps). A common, low-cost control module receiving the central-controller or local-control-apparatus information and directly controlling the output of the associated load is therefore highly desirable. It is also highly desirable to provide control of a load automatically responsive to local parameters, such as the intensity of ambient lighting (whereby energy consumption may be reduced when ambient light is sufficiently bright for local activity levels) and to set maximum users cannot exceed such load limitations.